Technical Abstract:
Commercial sugarbeet varieties with resistance to crown and root rot caused by Rhizoctonia are available; however, these varieties provide lower yields than susceptible varieties. Field tests were conducted to determine if use of mixtures of resistant and susceptible varieties could be used to minimize the losses due both to disease and to use of the resistant varieties. Yield losses associated with the resistant varieties were negligible when mixtures contained 1/6 or 1/3 of the resistant variety. Conversely, these same mixtures provided significant reductions in disease severity. Growers may benefit from reduction of disease severity and enhanced yields when using mixtures containing approximately 1/5 to 1/4 of the resistant variety under conditions where severe crown and root rot is anticipated.